1. Field of the Invention
This invention relates to a tool for stripping semiconducting insulation shield, and insulation if required, from an end part of a "polymeric" (as distinguished from paper-insulated) high-voltage cable in preparation for jointing or termination. For avoidance of doubt, any cable with at least one core of circular cross-section having a conductor shield and an insulation shield is to be considered a "high voltage" cable for the purposes of this invention.
The insulation of such cables is a large-section extrusion, and whereas its outer surface is nominally circular, minor inaccuracies in shape and dimension occur; these are of no significance in relation to the electrical function of the cable, provided that the surface is smooth and the radial thickness everywhere sufficient. However, in making joints and terminations, it is often necessary to use molded or otherwise preformed components that will not conform to such minor inaccuracies, and the part of the insulation from which the insulation shield has been removed needs to be cut to an accurately circular shape to avoid risk of electrical stress concentrations occuring locally in places between the exposed insulation and the preformed body.
2. Related Art
One known type of tool for stripping the insulation shield from such cables comprises an annular body carrying a stripping blade and means (such as a handle or a motor drive) for rotating the body around an end part of a cable extending through it to strip a surface layer from the cable in a generally helical manner. Such known tools do not generate a sufficiently circular stripped surface, because they are too much influenced by the precise radial dimensions of the cable at the position of the blade and at a place directly opposite it.